Traditionally, acoustic sensors employed for detecting sonic and ultrasonic emissions from selected material surfaces have used damped resonators to establish effective frequency range for operation.
The level of damping provided in such sensors has, however, generally been insufficient to enable an accurate level of broadband response indications completely covering a selected frequency range of primary interest, including, for example, the kilohertz and megahertz frequency domains.
Furthermore, prior designs previously employed have generally relied upon receipt of the acoustic signals over large contact areas by velocity sensitive detection elements. Such arrangements unfortunately grossly distort the received acoustic information.
It is accordingly an object of the invention to develop a compact, broadband point-contact acoustic transducer which minimizes contact area and enhances out of plane displacement sensitivity.
It is a further object of the invention to establish such a transducer, which does not require a coupling medium in order to detect displacement indications.